Microsoft Office 2016 (for Windows)

Pros

World's most powerful office suite.
Upgraded with the smoothest collaboration features anywhere.
Minimal interface changes from 2013 version.
Monthly updates with new features for Office 365 subscribers.
Consistent interface on all platforms, desktop and mobile.

Cons

Little-used features that were awkward in past versions still aren't fixed.
Traditional standalone copies won't get the same updates that Office 365 subscribers will get automatically.

Bottom Line

Microsoft Office remains the mightiest productivity suite you can get, with strong collaboration features added in the latest version.
Users of Office 2013 won't need any retraining, and new features are slotted smoothly in with the old.